System for the recovery of mineral oils



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'w. A. Looms Filed Maron 2.9, 1924 SYSTEM FOR THE RECOVERY OF MINERAL OILS sept. 22, 1925-.

@time Patented Sept. 22, 1925 UNITED STATES PATENT OFFICE.

WALTER A. LOOMIS, 0F LOS ANGELES, CALIFORNIA.

SYSTEM FOR THE RECOVERY OF MINERAL OILS.

Application filed March 29, 1924. SerialA No. 702,892.

To all whom t may cri/noem:

Be it known that I, WALTER A. LooMIs, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful System for the Recovery of Mineral Oils, of which the following is a speciflcation.

My present invention relates specifically to the recovery of mineral oils, and more particularly to a system effective for the conservation, control and utilization of relatively light or volatile hydrocarbons, including wild gases, such as are commonly present in large quantities in flowing oil wells at the time they first come into production.

It is known that, in the case of flowing oil wells, the delivery of oil in proportion to the highly volatile or gaseous hydrocarbons may average as low as one barrel to 10500 cubic feet of gas; and that, in many regions, all -or a very large part of this gas is permitted togo to waste. To avoid early loss of this gas, it has sometimes been shut in; but, when so shut in, it naturally rises above the liquid fractions, producing a downward pressure thereon and thereby tending to force the oil back into the rock, or sometimes out through competing wells. After large quantities of gas have gone to waste, a flowing well may cease to flow; and a reciprocating pump may be introduced at large cost only to reveal the fact that the ratio of gas to oil is still so high or so variable that economical production, or any production, is impossible. The objects of my invention include the providing of means for conserving wild gases in cases of the sorts referred to, and an ,improving of the ratio of oil to gas delivered. My invention is also suitable for use in bringing into production, or in restoring to production, numerous wells which have been abandoned, after drilling, because of a lack of proper means or methods for the recovery of oil therefrom. My invention comprises means and methods for obviating a sanding up of oil wells which seems frequently to result from sudden changes of pressure therein, and also means and methods permitting the repeated re-use of low-bo-iling hydrocarbons in the recovery of heavier hydrocarbons.

The principle of the air lift, involving a diminution in the weight of a column of water and an upward movement due to bubbles of air therein, is well known; but no introduction of mere air into a column of oil could produce the effects obtained in the Ypractice of my invention, which associates all the effects obtainable by an air lift with additional effects due to the relatively large solubility of gaseous or highly volatile hydrocarbons in heavier hydrocar-f bons or due to the fact that certain of the lighter hydrocarbons employed may undergo, in the practice of my invention, partial or complete change of phase, entering a pipe line as liquids, by reason of the pressures and other conditions prevailing at the level of their introduction, thereafter vaporizing and expanding at an increasing rate during their rise through regions o-f less pressure and toward a point of delivery.

It is an object of this invention to enable an oil well tol yield a controllable iiow up to the maximum rate of production of which it is capable, and to so conserve relatively volatile or gaseous hydrocarbons, naturally occuring or introduced into an oil well, as to maintain the flow for a long period of time.

It is an object of this invention to maintain at a suitable level within an oil well a mixer capable of introducing relatively volatile hydrocarbons into an oil tube containing heavier hydrocarbons, the pressure of said lighter hydrocarbons being effective initially to produce a difference in the level and subsequently to produce an upward movement in said heavier hydrocarbons, these results to be accomplished without forcing said heavier hydrocarbons back into the rock; and, in one advantageous embodiment of my invention, I may provide means at the t-op of a well casing for varying at will the rate of delivery of said lighter hydrocarbons to said miXer.

Other objects of my invention will appear from the following description of alternative embodiments thereof, taken in connection with the appended claims and the accompanying drawings in which Fig. l is a vertical section through the casing and tubes of an oil well yequipped Fig. 3 is a horizontal section taken substantially in the plane indicated by the line 3 3 of Fig. 2.

Fig. 4 is a similar section which may be regarded as taken substantially in the plane indicated b-y the line 4 4 of Fig. 1.

Referring to the details of that specic embodiment of my invention chosen for purposes of illustration, in Fig. 1, 11 may be the casing of an oil well, which may be assumed to extend substantially from the surface of the ground to the bottom of a well, the lower sections of this casing being shown as provided with holes or slots 12, through which liquid or gaseous hydrocarbons, or both, may enter said casing.

Within this casing, I may provide a string of tubing 13 for the upward delivery of oil; and this string may extend downward to a point below the level at which oil may normally stand within the oil well. To utilize the pressure of the lighter or gaseous hydrocarbons entering the casing 11, I may provide at the top of said casing, a closure, as by means of a cap itting 14, shown as connected with a pipe 15 having a hand valve 16, the closing of which may be effective to shut the well in dead at will. Uponwas;L

hns-accumulating within the casing 11, will then depress the outer oil level, the oil being permitted to rise freely within the tube 13, I may insert and support a mixer 17 at a level slightly above that to which the oil is capable of being depressed by a closure of the valve 16, the position and character of this mixer being such that, after the oil outside the same is lowered to the level of the openings 18 therethrough, the'entrance of lighter hydrocarbons through these openings may be eifective to produce an upward movement of oil within the tubing 13.

Although various alternative constructions might be employed for the purpose last referred to, I consider it advantageous to provide the mixer 17 with a gas jacket 19, shown as extending upwardly from the same and as provided with inlet ports 20. This gas jacket fitting may be secured to or integral with an intermediate fitting 21, which may be provided with a gland A22 to pack oif a section of inner oil tube 23, rising thereabove; and the fitting 21 may also be provided with means for threaded engagement with the tube 13, by which my mixer and the mentioned associated parts may be supported.

, By means such as have just been described, I may provide for a continuous and controllable admission, at high pressure, of gaseous or relatively volatile hydrocarbons into the mixer 17, regardless of minor fluc- -tuations in the level of the oil or in gas pressure. It will be understood that my mixer may ordinarily be installed at a level several thousand feet under ground, and at a considerableV distance from the bottom of a well; also that the absolute dimensions of the mentioned parts and the sizes and positions of the apertures therein must depend upon conditions of installation and use; but, under typical conditions, and assuming that gas is not to be initially conducted to the top of a well and then down again, for purposes of control, the gas acket 19 may have a length of 40 feet, more or less; and, in order to prevent gas from entering below my mixer, I may optionally secure to a lower connecting fit-ting 24, by which the mixer 17 is shown as connected to the gas `jacket 19, a skirt or downward extension 25, which may be a single length of pipe descending to such a low level as to insure its constant immersion in oil, even when a maximum gas pressure is built up.

It is found that an organization such as is above described may be eective not only to restore an abandoned well to production, but also to produce such an active and powerful iiow that the resultant mixture of oil and gas may be delivered at a considerable elevation or at a considerable lateral distance, such as a distance of a thousand feet or more, from the top of a well; and, ini order to permit of a re-use of gases or rela- 95 tively volatile hydrocarbons employed in .f the elevating of oil, or to permit of the use of an excess of wild gases or relatively voli atile hydrocarbons obtainable from one well in the elevation of oil in a neighboring well, k,100 I may provide means such as are diagram- 1, matically indicated in connection with Figi ure l. These means may comprise a lateral 26 extending to a tank 27, and a return pipe j' 28 leading from the top of said tank back 105 through the cap fitting 14, or otherwise into the interior of the casing 11. The return f pipe 28 may be provided with a pump 29, f for the reestablishment of pressure within the casing 11 and with valved branches 30, `110 31, through either of which gaseous or volatile hydrocarbons may be introduced from algggtglgllrce, and additional valved connectlons may be provided at 32, 33 and 34," to permit of any introduction or withdrawal: 115 of products, coming from the same or from, other wells, as convenience may require.: Depending upon the conditions of operation, either a pump or a valve may be introduced at 35 in the lateral 26.

It will be obvious that, when any natural iow of wild gases into a well is relied on to effect a delivery of oil therefrom, the inlet passages 18 of my mixer should be adapted to admit gas at only such a rate as to give 125 the desired ow, without materially changing the oil level or the gas pressure within the casing 11; and experimentation and calculation may make possible a predetermination of the proper size and number of the aper- 130 tures 18. If these apertures are slightly larger than may be required for a continuous flow, an intermittent flow may result, the oil rising, as the pressure is reduced, until kthe inlet openings 2O are temporarily submerged. As the pressure in the casing 11 builds up, there may be a recondensation of light hydrocarbons, which may' enter through the ports 20 and 18; and the presence of a high proportion of these relatively volatile hydrocarbons within the inner tube 23 or the tube 13 may, as they return to the vapor phase in consequence of the diminution of pressure therein, contribute materially to the lowered specific gravity and to the consequent unbalance and rise of the oil mixture,-their effects constituting an important supplement to the effects due to the dissolving of relatively light and volatile hydrocarbons in the heavier hydrocarbons, and both of these effects being entirely distinct from the essentially mechanical effects obtained in an ordinary air lift.

In order to permit of a complete manual control of the pressure within an outer casing, I may optionally employ an alternative construction such as is suggested in Fig. 2, in which the outer casing 11a is shown as provided with a cap 14a of special construction and comprising an inner section 14b including a partition element 14 adapted to support the tubing 13a, shown as extending continuously downward to an intermediate connecting fitting 21a supporting an oil pipe 23, carried to the top of the well and there provided with a gland engaging the cap section 14h. To permit of a controlled movement of gas or light hydrocarbons from the interior of the casing 11a into the space between the tubes 13a and 23a, I may provide an outlet 36 from the outer section of the cap 14a, and a pipe 37, leading into the interior of the cap section 14h, these pipes 36 and 37 being shown as connected by a valved pipe 38. By this construction, gas or light hydrocarbons arising'within the casing 11` may be delivered, under complete control, into the space between the tubes 13a and 23a; and, to permit the descent `of this gas or any light hydrocarbons, to a mixer such as is shown in Fig. 1, instead of running the tubing 13a directly to the mixer, I may employ an intermediate connecting fitting 21a having vertical passages 39, extending into the gas space provided by the jacket 19a, the said jacket and the tube 13 being shown as respectively connected to the intermediate fitting 52,12L by couplings 40 and 11. An intermediate fitting Qla may be used either in connection with a double string of tubing, as shown in Fig. 2, or in connection with a single string, as shown in Fig. 1, and, to permit of these alternative modes of use, I may optionally provide the fitting 21a with lateral openings 20a, shown as closed by plugs 20h,

`ated bymthe vap rrzation ofnlight it being understood that when this fitting is to be used in such an organization as is shown in Fig. 1, these plugs 20b may be shifted to engage the threads 20c, and thereby close the tops of the vertical passages 39. Except as indicated, it will be understood that all of the auxiliary devices referred to in connection with Fig. 1 may optionally be used also in connection with such an organization as is disclosed in Fig. 2, an additional valved passage for the admission or withdrawal of gas being indicated at 42; and it will also be understood that, although apparatus is required in the practice of my invention, the present disclosure of apparatus is merely diagrammatic, similar results being obtainable by the use of simpler or equivalent constructions.

In general, it is important that the foot piece or mixer 17 should be installed at such a level in the well as to maintain as high a 'pressure at the mixer as is possible without setting up an undue back pressure, tending to prevent the oil from coming freely into the well. The pressure of the gas on the oil in the casing, outside the tubing, will cause the oil to rise to a point in the tubing above the outside level, this distance in feet corresponding to the head in pounds on the gas. As stated, the ideal point for the mixer mayv be slightly abo-ve the level taken by the oil in the casing when the well is shut in dead and the pressure built up. After installa=\f tion, the casing head or cap being shut, the

gas is allowed to accumulate in the casing until the pressure drives 'the oil down to the level of the mixer; then, if the mixer has been installed at the proper level, the/gas-lv i 'I Will begin-810mm@ Hematite 9il...n.-th@ wilma--Owing taille slisl b "1 bons and'v thwexpa'n'sionl of gasfpioduc'ingv larger and larger bubbles in the oil within the tubing. Since the gas, or mixture of gas and readily volatile hydrocarbons, goes into the oil under pressure and in a finely divided form, certain portions thereof, probably including those hydrocarbons in the paraffin series below propane, are absorbed by the oil. Liquid hydrocarbons may, in fact, be carried down to the mixer, t0 be volatilized by contact with the warmer oils therein. As the oil mixture rises higher in the tubing, thereby releasing the pressure,

a column of constantly effervescing oil with a greatly reduced weight will actually foamf over the top, causing the well to flow. Instead of requiring a thousand feet of gasi` to deliver a barrel of oil, as in naturallyi flowing wells, my system may, however, re- 1,125

quire about 100 feet of gas per barrel of oil produced. My method involves no sudden changes in pressure tending to cause a i well to sand up, and it moreover solves the problems which arise when a well. is

making too much gas to pump and not sufficient to flow in the usual way. It will also conserve the gas in new wells, maintaining the pressure for a much greater length of time, and thereby holding the water ou't of the formation and pro-longing the life of the well. By bringing wells into production in series, the rush of gas, rich in wild fractions, from a new well, may, moreover, be utilized in continuing the production of an older well or wells. The use of reciprocating pumps in wells which yield or which may receive gaseous or light hydrocarbons, becomes unnecessary.

It is believed that the intended modes of using my described apparatus and system will be fully understood from the foregoing description, in connection with which I desire especially to emphasize the novelty of my method, as distinguished from my apparatus, it being understood that numerous modifications in both might be made, by those skilled in the art, without the slightest departure from the spirit and scope of my invention, as the same is indicated above and in the following claims.

I claim as my invention:

l. In an organization for the elevation of oil from wells containing no mechanical pumps, the combination of: a casing, an inner oil delivery tube, a mixer supported wit-hin said casing above the level to which oil may be depressed within said casing but below the level to which oil may rise in said tube when the well is shut in dead, means for maintaining easily volatilizable hydrocarbons under pressure within said casing, and means for delivering both oil and said easily volatilizable hydrocarbons under substantially the same pressure to said mixer.

2. In an organization, as described in claim l, a gas jacket connected with said mixer and provided with means for admitting said easily volatilizable hydrocarbons at a level above said mixer.

3. In an organization as described in claim l, means for preventing entrance of easily volatilizable hydrocarbons at a level below said mixer.

4. In an organization for the recovery of oil from wells containing no mechanical pumps, the combination of: a casing, an oil tube, means for controlling the flow of easily volatilizable hydrocarbons to and from said casing to predetermine a pressure therein, and means for introducing said easily volatilizable hydrocarbons into said oil tube under pressure at a level below that to which oil may be forced by said pressure to rise in said oil tube but above that to which said oil may then be forced downward in said casing.

5. In an organization for the recovery of oil from wells containing no mechanical i 1 M23? Ay pumps, means for introducing a iiuid in vapor phase under pressure and at low velocity below a surface of a body of relatively heavy hydrocarbons within an oil Well and while said oil is elevated in an oil delivery tube and depressed in a casing by the pressure of volatile hydrocarbons therein.

6. In the elevating of relatively heavy oils, the' method which comprises introducing a stream of a relatively volatile hydrocarbon at a lower temperature below a surface of a body of the relatively heavy hydrocarbon oil at a temperature favorable to a change of phase of said relatively volatile hydrocarbons and while said oil is elevated in an oil delivery tube and depressed in a casing by the pressure of volatile hydrocarbons therein. y

`7. The method of elevating relativelyfy heavy hydrocarbon oil which comprises add;y mixing relatively volatile hydrocarbonsl therewith, under conditions favorable to change of phase of said volatile hydrocar-,f' bons during an ascending movement of the mixture and while said oil is elevated in 90 an oil delivery tube and depressed in a cas- "I, ing by the pressure of volatile hydrocarbons therein.

8. The method of utilizing volatile hydrocarbons and promoting oil iloyrgr g prises conducting sucliduymrocarbons from oaawellitaaraiatlloa uiii-r-Y'Sif-f'" ofd aflidyuofoil eldaunder, ressureinam othenwelland while said oil is elevated in an oil tube and Wdepressed in a casing by the pressure of said volatile hydrocarbons in said last mentioned well.

9. The method of obtaining oil from wells containing gas which comprises: preventing the upward escape of gas from such a Well having both a casing and an oil delivery tube to a submerged portion 0f which oil ,f

is freely admitted otinfr thewihs'pec ive levels at which the resaitgpressure rna'yIIdl-d l thi 011 inside and outside the oil dem@ 1MLl t a mixer having gas inlets placed at a level slightly above that to which said. gas is found to be able to depress said oil outside said delivery pipe but below the consequent level of oil within said tube; and admitting oil and gas at substantially the same pressure to said mixer.

10. In a method as defined in claim 9, permitt-ing said gas slowly to enter and to rise and to expand in said tube in such manner as to produce an unbalance favorable to the continuous upward delivery of oil therethrough.

11. In a method as defined in claim 9, so proportioning the admission of gas to said mixer as to maintain an optimum pressure and consequent iow of mixed gas and oil within said delivery pipe.

12. In a method as defined in claim 9,

admitting through said gas inlets a mixture comprising relatively volatile hydrocarbons in a state of condensation, and permitting the same to undergo a change of phase in said oil delivery pipe.

13. In an organization for the elevation of oil from Wells, an outer Casing provided with means for controlling a flow of gas relatively thereto; an oil delivery tube With- 10 in said easing; a mixer carried by said oil delivery tube and provided With an oil inlet at its bottom and With lateral gas inlets; a gas jacket surrounding and extending above said mixer and there provided with gas-admission apertures opening into the space between said j aoket and said casing.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 21st day of March, 1924.

WALTER A. LOOMIS. 

